This invention is related to U.S. application No. 08/347,537, filed Nov. 30, 1994, filed on even date herewith. With the advent of optical fiber communications, a need has developed for relatively low cost, high efficiency and single frequency light emitting devices. Such devices allow for reliable sources with which to effect the various modulation schemes, such as frequency shift keying (FSK) and phase shift keying (PSK) as well as other WDM techniques. Ring lasers are quickly becoming a suitable light source for such applications, and strides have been made to modify and/or improve the basic ring laser to effect a desired light output. An example of such a ring laser is found in U.S. Pat. No. 5,132,976, to Chung, et al, the disclosure of which is specifically incorporated herein by reference. The '976 reference discloses the use of a fiber Fabry-Perot etalon, a F-P etalon in which two mirrors are made by depositing coatings on the polished ends of single mode fiber, to effect wavelength selectivity. The tuning of the FFP is effected by electrically controlling the gap of the etalon, and the FFP boasts a finesse of 55. The ring laser cavity which includes a section of erbium doped fiber which serves to enable the gain of the ring to exceed the loss, thereby permitting lasing. Recognizing that the FFP cannot be used as a standing wave resonator as it will reflect wavelengths outside the passband and act as a resonator for those wavelengths, the invention discloses the use of an in line optical isolator. The isolator serves to suppress standing wave laser modes generated by the FFP reflections which are outside the FFP passband, allowing lasing to occur within the passband of the FFP, as desired. Finally, a polarization controller is included in the ring for the purpose of maximizing the output power. Another example of the use of a ring laser for a stable source of light at a select frequency is found in U.S. Pat. No. 5,243,609 to Huber, the disclosure of which is specifically incorporated herein by reference. The Huber reference discloses the drawbacks of the use of Er.sup.3+ as a gain medium in a ring laser, one drawback being the existence of multiple longitudinal modes. Longitudinal modes in this instance can be close enough to one another to result in a beat manifesting in the rf range, an unacceptable result in many communications applications. The reference discloses the suppression of undesired modes that result in beating about the rf band. The reference discloses the use of a Fabry-Perot etalon as one method of suppressing undesired longitudinal modes by choosing the cavity lengths to support a selected mode(s). The reference also discloses the use of an optical isolator to ensure wave oscillation in one ring direction. Finally, a Fabry-Perot interferometer pair of unequal length provide wavelength selectivity within the ring laser.